1. Field of the Invention
This invention relates to a plate-shaped substrate for building up a module with mechanical, electronic or optical components with local heating resistors for applying heat during the fastening of the components to fastening positions on the substrate, and to a thus built up module and a method for fastening components to such a substrate.
2. Discussion of Related Technology
A substrate and a module of the described type have become known from GB 8 609 858. The known module contains an end of an optical glass fiber fastened to a substrate, a diode laser coupled optically to this fiber end, and further optical and electronic components. The fiber end is soldered on the substrate by briefly heating the substrate during the soldering process through a thick-film resistor mounted in the area of a metalized fastening position.
The substrate consists of a ceramic plate with ground surfaces and conductive paths applied by thick-film technology and then covered with an insulating layer. In the area of the fastening position for the fiber end a thick-film resistor with leads is disposed on the insulating layer and covered with a second insulating layer. On this second insulating layer a metalized surface is provided over the thick-film resistor.
During assembly of the module the fiber end is suitably aligned on the metalized surface and the thick-film resistor heated by supplied current, which causes supplied solder to melt. Then the supply of current is interrupted, the solder hardens and fixes the fiber end.
The disadvantage of the known module is that up to six layers of conductive and nonconductive material must be disposed one on the other on the substrate. This makes production elaborate and expensive and the stability of the layer structure can suffer.
The objective of this invention is to provide a substrate and a module to be built up therewith of the described type which avoids the disadvantages of the known module.